scholarly journals A Novel Deaminase Involved in Chloronitrobenzene and Nitrobenzene Degradation with Comamonas sp. Strain CNB-1

2007 ◽  
Vol 189 (7) ◽  
pp. 2677-2682 ◽  
Author(s):  
Lei Liu ◽  
Jian-Feng Wu ◽  
Ying-Fei Ma ◽  
Sheng-Yue Wang ◽  
Guo-Ping Zhao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Bacterial Growth ◽  
Bradyrhizobium Japonicum ◽  
Catalytic Mechanism ◽  
Rhodopseudomonas Palustris ◽  
Hydroxyl Group ◽  
Hypothetical Proteins ◽  
Terminal Sequence ◽  
Significant Similarity ◽  
Carbon And Nitrogen

ABSTRACT Comamonas sp. strain CNB-1 degrades nitrobenzene and chloronitrobenzene via the intermediates 2-aminomuconate and 2-amino-5-chloromuconate, respectively. Deamination of these two compounds results in the release of ammonia, which is used as a source of nitrogen for bacterial growth. In this study, a novel deaminase was purified from Comamonas strain CNB-1, and the gene (cnbZ) encoding this enzyme was cloned. The N-terminal sequence and peptide fingerprints of this deaminase were determined, and BLAST searches revealed no match with significant similarity to any functionally characterized proteins. The purified deaminase is a monomer (30 kDa), and its V max values for 2-aminomuconate and 2-amino-5-chloromuconate were 147 μmol·min−1·mg−1 and 196 μmol·min−1·mg−1, respectively. Its catalytic products from 2-aminomuconate and 2-amino-5-chloromuconate were 2-hydroxymuconate and 2-hydroxy-5-chloromuconate, respectively, which are different from those previously reported for the deaminases of Pseudomonas species. In the catalytic mechanism proposed, the α-carbon and nitrogen atoms (of both 2-aminomuconate and 2-amino-5-chloromuconate) were simultaneously attacked by a hydroxyl group and a proton, respectively. Homologs of cnbZ were identified in the genomes of Bradyrhizobium japonicum, Rhodopseudomonas palustris, and Roseiflexus sp. strain RS-1; these genes were previously annotated as encoding hypothetical proteins of unknown function. It is concluded that CnbZ represents a novel enzyme that deaminates xenobiotic compounds and/or α-amino acids.

Access to 2-Arylquinazolines via Catabolism/Reconstruction of Amino Acids with Insertion of Dimethyl Sulfoxide

2021 ◽  
Author(s):  
Jin-Tian Ma ◽  
Li-Sheng Wang ◽  
Zhi Chai ◽  
Xin-Feng Chen ◽  
Bo-Cheng Tang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dimethyl Sulfoxide ◽  
Nitrogen Source ◽  
Carbon And Nitrogen ◽  
First Time

Quinazoline skeletons are synthesized by amino acids catabolism/reconstruction combined with dimethyl sulfoxide insertion/cyclization for the first time. The amino acid acts as a carbon and nitrogen source through HI-mediated catabolism...

Growth Conditions of a Thermophilic Geobacillus sp. as an Enhanced Oil Recovery Material

2012 ◽  
Vol 496 ◽  
pp. 457-460
Author(s):  
Xiang Ping Kong
Keyword(s):  
Enhanced Oil Recovery ◽  
Bacterial Growth ◽  
Oil Recovery ◽  
Nitrogen Sources ◽  
Growth Conditions ◽  
Good Growth ◽  
Strictly Aerobic ◽  
Aerobic Bacterium ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen

The growth conditions of a Geobacillus sp. were investigated by single-factor experiments. The strain was strictly aerobic bacterium, and could grow on hydrocarbons as the sole carbon source. The optimum carbon and nitrogen sources were 3.0% sucrose and 0.20% KNO3, respectively. The range of temperature, salinity and pH for the bacterial growth was 35-70 °C, 0-10% NaCl and 5.5-9.5, and good growth was obtained at 35-65 °C, 0.5-8% NaCl and 6.0-9.0, respectively. Particularly, the optimum temperature for the bacterial growth was between 50 °C and 60 °C. The strain had wide adaptability to the extreme conditions, and may be potentially applied to microbial enhanced oil recovery and oil-waste bioremediation technology.

The C-terminal sequence of amino acid residues of κ-casein isolated from buffalo's milk

1967 ◽  
Vol 34 (1) ◽  
pp. 85-88 ◽  
Author(s):  
M. H. Abd El-Salam ◽  
W. Manson
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Peptide Chain ◽  
Amino Acid Residues ◽  
Terminal Sequence ◽  
Carboxypeptidase A ◽  
Phosphorous Content ◽  
Single Peptide

SummaryWhen κ-casein from buffalo's milk was treated with carboxypeptidase A (EC 3. 4. 2. 1),4 amino acids, valine, threonine, serine and alanine were released from the protein in a manner consistent with the view that they originate in the C-terminal sequence of a single peptide chain. The amounts produced suggest a minimum molecular weight for buffalo κ-casein of approximately 17000, in agreement with the value calculated from the phosphorous content on the basis of the presence of 2 phosphorus atoms/molecule. A comparison is made with the C-terminal sequence reported for bovine κ-casein.

scholarly journals Identification and Characterization of Cotinine Hydroxylase CotA that Initiates biodegradation of Wastewater Micropollutant Cotinine in Nocardioides sp. Strain JQ2195

2021 ◽  
Author(s):  
Lingling Zhao ◽  
Zhenyang Zhao ◽  
Kaiyun Zhang ◽  
Xuan Zhang ◽  
Siqiong Xu ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Tobacco Consumption ◽  
Hydroxyl Group ◽  
Carbon And Nitrogen ◽  
Enzymatic Transformation ◽  
Degrading Bacterium ◽  
Hydroxylase Gene ◽  
Urine Cotinine ◽  
Genetic Mechanisms

Cotinine is a stable toxic contaminant, produced as a byproduct of smoking. It is of emerging concern due to its global distribution in aquatic environments. Microorganisms have the potential to degrade cotinine, however, the genetic mechanisms of this process are unknown. Nocardioides sp. strain JQ2195 is a pure culture strain that has been reported to degrade cotinine at micropollutant concentrations. This strain utilizes cotinine as its sole carbon and nitrogen source. In this study, a 50 kb gene cluster (designated as cot ) involved in cotinine degradation, was predicted based on genomic and transcriptomic analyses. A novel three-component cotinine hydroxylase gene (designated as cotA1A2A3 ), which initiated cotinine catabolism was identified and characterized. CotA from Shinella sp. HZN7 was heterologously expressed and purified, and shown to convert cotinine into 6-hydroxycotinine. H 2 18 O-labelling and ESI-MS analysis confirmed that the hydroxyl group incorporated into 6-hydroxycotinine was derived from water. This study provides new molecular insights into the microbial metabolism of heterocyclic chemical pollutants. IMPORTANCE In the human body, cotinine is the major metabolite of nicotine, and 10–15% of generated cotinine is excreted in urine. Cotinine is a structural analogue of nicotine and is much more stable than nicotine. Increased tobacco consumption has led to high environmental concentrations of cotinine, which may have detrimental effects on aquatic ecosystems and human health. Nocardioides sp. strain JQ2195 is a unique cotinine-degrading bacterium. However, the underlying genetic and biochemical foundations of cotinine degradation are still unknown. In this study, a 50 kb gene cluster (designated cot ) was identified by genomic and transcriptomic analyses as being involved in the degradation of cotinine. A novel three-component cotinine hydroxylase gene (designated cotA1A2A3 ) catalyzed cotinine to 6-hydroxy-cotinine. This study provides new molecular insights into the microbial degradation and enzymatic transformation of cotinine.

scholarly journals Amino Acid-Mediated Induction of the Basic Amino Acid-Specific Outer Membrane Porin OprD from Pseudomonas aeruginosa

1999 ◽  
Vol 181 (17) ◽  
pp. 5426-5432 ◽  
Author(s):  
Martina M. Ochs ◽  
Chung-Dar Lu ◽  
Robert E. W. Hancock ◽  
Ahmed T. Abdelal
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Regulatory Protein ◽  
Basic Amino Acid ◽  
Sole Source ◽  
Activation Mechanism ◽  
Beta Lactam ◽  
Mobility Shift ◽  
Carbon And Nitrogen

ABSTRACT Pseudomonas aeruginosa can utilize arginine and other amino acids as both carbon and nitrogen sources. Earlier studies have shown that the specific porin OprD facilitates the diffusion of basic amino acids as well as the structurally analogous beta-lactam antibiotic imipenem. The studies reported here showed that the expression of OprD was strongly induced when arginine, histidine, glutamate, or alanine served as the sole source of carbon. The addition of succinate exerted a negative effect on induction ofoprD, likely due to catabolite repression. The arginine-mediated induction was dependent on the regulatory protein ArgR, and binding of purified ArgR to its operator upstream of theoprD gene was demonstrated by gel mobility shift and DNase assays. The expression of OprD induced by glutamate as the carbon source, however, was independent of ArgR, indicating the presence of more than a single activation mechanism. In addition, it was observed that the levels of OprD responded strongly to glutamate and alanine as the sole sources of nitrogen. Thus, that the expression ofoprD is linked to both carbon and nitrogen metabolism ofPseudomonas aeruginosa.

scholarly journals Comparative Genomics of Ethanolamine Utilization

2009 ◽  
Vol 191 (23) ◽  
pp. 7157-7164 ◽  
Author(s):  
Olga Tsoy ◽  
Dmitry Ravcheev ◽  
Arcady Mushegian
Keyword(s):  
Computational Analysis ◽  
Catalytic Mechanism ◽  
Food Poisoning ◽  
Structural Components ◽  
Carbon And Nitrogen ◽  
Dna Motif ◽  
Serovar Typhimurium ◽  
Tim Barrel ◽  
Per Se ◽  
Horizontal Transfers

ABSTRACT Ethanolamine can be used as a source of carbon and nitrogen by phylogenetically diverse bacteria. Ethanolamine-ammonia lyase, the enzyme that breaks ethanolamine into acetaldehyde and ammonia, is encoded by the gene tandem eutBC. Despite extensive studies of ethanolamine utilization in Salmonella enterica serovar Typhimurium, much remains to be learned about EutBC structure and catalytic mechanism, about the evolutionary origin of ethanolamine utilization, and about regulatory links between the metabolism of ethanolamine itself and the ethanolamine-ammonia lyase cofactor adenosylcobalamin. We used computational analysis of sequences, structures, genome contexts, and phylogenies of ethanolamine-ammonia lyases to address these questions and to evaluate recent data-mining studies that have suggested an association between bacterial food poisoning and the diol utilization pathways. We found that EutBC evolution included recruitment of a TIM barrel and a Rossmann fold domain and their fusion to N-terminal α-helical domains to give EutB and EutC, respectively. This fusion was followed by recruitment and occasional loss of auxiliary ethanolamine utilization genes in Firmicutes and by several horizontal transfers, most notably from the firmicute stem to the Enterobacteriaceae and from Alphaproteobacteria to Actinobacteria. We identified a conserved DNA motif that likely represents the EutR-binding site and is shared by the ethanolamine and cobalamin operons in several enterobacterial species, suggesting a mechanism for coupling the biosyntheses of apoenzyme and cofactor in these species. Finally, we found that the food poisoning phenotype is associated with the structural components of metabolosome more strongly than with ethanolamine utilization genes or with paralogous propanediol utilization genes per se.

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